He made unsubstantiated claims Saturday that Obama had wire tapped Trump in the month leading up to Election Day. Obama spokesperson Kevin Lewis denied the allegation, but the White House has asked Congress to look into the issue.

“Reports concerning potentially politically motivated investigations immediately ahead of the 2016 election are very troubling,”Press Secretary Sean Spicer tweeted. “President Trump is requesting that as part of their investigation into Russian activity, the congressional intelligence committees exercise their oversight authority to determine whether executive branch investigative powers were abused in 2016.”

Trump has offered no evidence to support his claims, but Spicer said the White House will not comment on the issue any further until the committees conclude their work.

If federal agents had been legally wiretapping Trump’s phone conversations, it would mean the Justice Department had provided sufficient evidence to a federal judge for a warrant.

Lewis, called “any suggestion” that Obama or any White House official ordered surveillance against Trump “simply false.”

“A cardinal rule of the Obama administration was that no White House official ever interfered with any independent investigation led by the Department of Justice,” Lewis said in a statement early Saturday afternoon. “As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any US citizen. Any suggestion otherwise is simply false.”